Optical connector plug, optical connector adapter and optical connector

ABSTRACT

To provide an optical connector promoting reliability by reducing insertion loss of an optical fiber and downsized, there is provided an optical connector plug having a ferrule including a cylindrical member for the ferrule for holding an optical fiber and a flange member provided at a rear end portion of the cylindrical member for the ferrule, an urge spring provided on a side of a rear end portion of the flange member of the ferrule, and a plug housing for holding the ferrule and the urge spring directly at inside thereof and directly engaged with an optical connector adapter inserted with a front end portion of the ferrule to carry out optical connection, in which the plug housing is formed with a slit capable of inserting the optical fiber in a radius direction thereof at a portion of an outer periphery thereof over an axial direction.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an optical connector plug and anoptical connector adapter as well as an optical connector for holding afront end of an optical fiber and optically connecting the opticalfibers.

[0003] 2. Description of the Related Art

[0004] In a related art, optical connection of optical fibers used inoptical communication is carried out by a method of using an opticalconnector having an optical connector plug holding a front end of theoptical fiber and an optical connector adapter for carrying out opticalconnection of the optical fibers by fixing the optical connector plugs,or a method of welding front end faces of the optical fibers.

[0005] According to the optical connection of theoptical fibers bywelding, there pose a problem that attachment and detachment of theoptical connection of the optical fibers cannot be carried out, and aproblem that welding steps are complicated which gives rise to a problemthat there is a restriction in use thereof.

[0006] Further, according to an optical connector of an SC type, an FCtype or the like for carrying out optical connection by using acylindrical member for a ferrule holding an optical fiber and having anouter diameter of φ2.5 mm, the optical connector cannot be downsized anda wide mounting area is needed in mounting the optical connector to amounting board.

[0007] Therefore, there has been proposed an MU type optical connectorusing a cylindrical member for a ferrule holding an optical fiber andhaving an outer diameter of φ1.25 mm and comparatively downsized (forexample, refer to nonpatent. literature 1).

[0008] According to the MU type optical connector, an optical connectorplug and an optical connector adapter are difficult to disengage fromeach other and reliability of optical connection can be promoted.However, such an MU type optical connector is generally designed tocarry out optical connection using an optical fiber cord provided with atension member and a coating further on an outer periphery of an opticalfiber core line provided with a coating on an outer periphery of anoptical fiber to carry out optical connection at a panel face on anouter side of an optical transmission apparatus. Therefore, a number ofparts is large and downsizing thereof is difficult. Therefore, a widemounting are is needed for mounting a comparatively small-sized MU typeoptical connector at a mounting board and there poses a problem thatdownsizing of the mounting board per se cannot be achieved.

[0009] Further, when the optical connector of the related art is mountedto the mounting board, the optical adapter is directly fixed to themounting board and therefore, a space for attaching and detaching theoptical connector plug holding the optical fiber is needed on themounting board and there poses a problem that not only the mountingboard is large-sized but also operational efficiency is poor.

[0010] Further, there poses a problem that numbers of parts are largeand integration is difficult in respectives of the optical connectorflag and the optical connector adapter of the optical connector of therelated art.

[0011] In order to resolve such a problem, there has been proposed anoptical connector for urging to hold a ferrule holding an optical fiberto a side of a front end face thereof in an axial direction by a leafspring fixed to a mounting board to thereby bring the front end faces ofthe ferrules into contact with each other by predetermined pressure (forexample, refer to patent literatures 1 and 2).

Patent Literature 1

[0012] JP-A-2-259708 (pages 1 through 2, FIGS. 1 through 3)

Patent Literature 2

[0013] JP-UM-A-6-73705 (page 5, FIG. 1)

Nonpatent Literature 1

[0014] Japanese Industrial Standards (JIS) C5983 F14 type connector

[0015] However, according to the above-described optical connector usingthe leaf spring, there poses a problem that owing to durabilityperformance of the leaf spring, when attachment and detachment arerepeated, durability of the leaf spring is deteriorated, a deteriorationin opposing connection of optical fibers, that is, a deterioration ininsertion loss is brought about and therefore, a number of times ofattachment and detachment is restricted.

[0016] Further, according to the above-described optical connector usingthe leaf spring, there is not means for restricting movement of theferrule holding the front end of the optical fiber in a rotatingdirection centering on an axis thereof, an eccentric direction of thecore of the optical fiber cannot be prescribed and the inserting loss isincreased by bringing about an eccentric shift of the core.

[0017] Further, according to the above-described optical connector usingthe leaf spring, there poses a problem that the ferrule is liable todisengage from the leaf spring by vibration and impact and thereliability is poor.

[0018] Further, according to the above-described optical connector usingthe leaf spring, the front end portion of the cylindrical body forferrule is directly inserted into a sleeve for optical connection andtherefore, there poses a problem that a defect is liable to be broughtabout at the polished front end face of the cylindrical member forferrule when an inserting angle is large or by repeating attachment anddetachment, the inserting loss in optical connection is liable toincrease and the reliability is poor.

SUMMARY OF THE INVENTION

[0019] It is a problem of the invention to provide an optical connectorpromoting reliability by reducing insertion loss of an optical fiber anddownsized in view of such a situation.

[0020] In order to resolve the above-described problem, according to afirst aspect of the invention, there is provided an optical connectorplug comprising a ferrule including a cylindrical member for the ferrulefor holding an optical fiber and a flange member provided at a rear endportion of the cylindrical member for the ferrule, an urge springprovided on a side of a rear end portion of the flange member of theferrule, and a plug housing for holding the ferrule and the urge springdirectly at inside thereof and directly engaged with an opticalconnector adapter inserted with a front end portion of the ferrule tocarry out optical connection, wherein the plug housing is formed with aslit capable of inserting the optical fiber in a radius directionthereof at a portion of an outer periphery thereof over an axialdirection.

[0021] According to a second aspect of the invention, there is providedthe optical connector plug according to the first aspect, wherein therear end portion of the flange member is provided with an engagingportion for engaging with the plug housing and the plug housing includesa holding hole for holding the ferrule in a state of being urged by theurge spring to a front end side in the axial direction by engaging withthe engaging portion of the flange member and a first rotation stopperportion engaged with the flange member for restricting movement of theferrule in a rotating direction centering on an axis thereof.

[0022] According to a third aspect of the invention, there is providedthe optical connector plug according to the second aspect, wherein thefirst rotation stopper portion of the plug housing is provided to beable to change relative positions of the plug housing and the ferrule ina state in which the ferrule is pushed against the urge spring.

[0023] According to a fourth aspect of the invention, there is providedthe optical connector plug according to any one of the first through thethird aspects, wherein the flange member is engaged with the opticalconnector adapter to restrict the ferrule from moving in the rotatingdirection centering on the axis of the ferrule.

[0024] According to a fifth aspect of the invention, there is providedthe optical connector plug according to any one of the second throughthe fourth aspects, wherein the flange member includes an outerperiphery a section of which is rectangular, and the ferrule isrestricted from moving in the rotating direction by bringing the firstrotation stopper portion into contact with two faces of an outerperipheral face of the flange member on one side opposed to each otherand bringing two faces of the flange member on other side into contactwith the optical connector adapter.

[0025] According to a sixth aspect of the invention, there is providedthe optical connector plug according to any one of the first through thefourth aspects, wherein the outer peripheral face of the flange memberis provided with an urge spring engaging projection projected over thecircumferential direction for engaging with the urge spring.

[0026] According to a seventh aspect of the invention, there is providedthe optical connector plug according to any one of the first through thesixth aspects, wherein an outer diameter of the cylindrical member forthe ferrule is 1.25 mm.

[0027] According to an eighth aspect of the invention, there is providedan optical connector including the optical connector plug according toany one of the first through the seventh aspects.

[0028] According to a ninth aspect of the invention, there is providedan optical connector adapter comprising a sleeve for optical connectioninserted with ferrules holding optical fibers from sides of both endsthereof for bringing end faces of the ferrules into contact with eachother to be connected optically, and an adapter housing holding thesleeve for optical connection and optically coupling optical connectorplugs held by the ferrules, wherein an outer periphery of the adapterhousing is provided with a first mount engaging portion attachably anddetachably engaging with a mounting board or amounting member attachablyand detachably fixed to the mounting board to project from one facethereof.

[0029] According to a tenth aspect of the invention, there is providedthe optical connector adapter according to the ninth aspect, wherein theadapter housing comprising a housing main body provided by integralmolding to open a sleeve inserting hole inserting to hold the sleeve foroptical connection on one side of a side face thereof, and a lid memberfitted to the sleeve inserting hole of the housing main body, whereinthe lid member is integrally provided with the first mount engagingportion projected to a side of other face of the housing main body.

[0030] According to an eleventh aspect of the invention, there isprovided the optical connector adapter according to the tenth aspect,wherein engagement of the lid member by the first mount engaging portionis disengaged by an attaching and detaching jig.

[0031] According to a twelfth aspect of the invention, there is providedthe optical connector adapter according to the eleventh aspect, whereinthe attaching and detaching jig is, provided with a shape of a pin andthe engagement is disengaged by elastically deforming the first mountengaging portion by inserting the attaching and detaching jig betweenthe first mount engaging portion and the housing main body.

[0032] According to a thirteenth aspect of the invention, there isprovided the optical connector adapter according to the ninth aspect,wherein the adapter housing is formed by integral molding and the oneface of the adapter housing is provided with a sleeve inserting hole forinserting the sleeve for optical connection.

[0033] According to a fourteenth aspect of the invention, there isprovided the optical connector according to any one of the ninth throughthe thirteenth aspects, wherein an inner side of an outer edge of anopening of the sleeve inserting hole is provided with a projection ofthe sleeve brought into contact with an outer peripheral face of thesleeve for optical connection for preventing detachment from the sleeveinserting hole.

[0034] According to a fifteenth aspect of the invention, there isprovided the optical connector adapter according to any one of the ninththrough the fourteenth aspects, wherein the side of the other face ofthe adapter housing is provided with a second mount engaging portion forengaging with the first mount engaging portion of other one of theadapter housing.

[0035] According to a sixteenth aspect of the invention, there isprovided the optical connector adapter according to the fifteenthaspect, wherein a plurality of pieces of the adapter housings arelaminated.

[0036] According to a seventeenth aspect of the invention, there isprovided the optical connector adapter according to any one of the ninththrough the sixteenth aspects, wherein the adapter housing is providedwith a second rotation stopper portion engaged with an outer peripheryof the ferrule for restricting the ferrule from moving in a rotatingdirection.

[0037] According to an eighteenth aspect of the invention, there isprovided an optical connector comprising the optical connector adapteraccording to any one of the ninth through the seventeenth aspects.

[0038] According to a nineteenth aspect of the invention, there isprovided an optical connector comprising a ferrule comprising acylindrical member for the ferrule holding a front end of an opticalfiber and a flange member fitted to a rear end portion thereof andincluding an engaging portion on a side of a rear end portion of theflange member, an optical connector plug comprising an urge springprovided on the side of the rear end portion of the flange member of theferrule, and a plug housing directly holding the ferrule in a state ofbeing urged to a side of a front end thereof in an axial direction bythe urge spring by being engaged with the engaging portion of theferrule and provided with a slit capable of inserting the optical fiberin a radius direction thereof at a portion of an outer periphery thereofover the axial direction and an optical connector adapter comprising asleeve for optical connection inserted with the cylindrical members forthe ferrules from sides of both ends thereof for bringing end faces ofthe cylindrical members for the ferrules into contact with each other tooptically connect, and an adapter housing holding the sleeve for opticalconnection and having a shape for optically coupling the opticalconnector plugs, wherein the plug housing and the adapter housing areformed with engaging portions for engaging the plug housing and theadapter housing with each other, an outer periphery of the adapterhousing is provided with a first mount engaging portion for attachablyand detachably engaging with a mounting board or a mounting member fixedattachably and detachably to the mounting board to project from one facethereof.

[0039] According to a twentieth aspect of the invention, there isprovided the optical connector according to the nineteenth aspect,wherein the plug housing is provided with a first rotation stopperportion engaged with the flange member for restricting the ferrule frommoving in a rotating direction centering on an axis thereof and theadapter housing is provided with a second rotation stopper portionengaged with the flange member of the optical connector plug engagedwith the adapter housing for restricting the ferrule from moving in therotating direction centering on the axis of the ferrule.

[0040] According to a twenty-first aspect of the invention, there isprovided the optical connector according to the twentieth aspect,wherein the flange member is provided with an outer periphery having asection in a rectangular shape and the ferrule is restricted from movingin the rotating direction by bringing the first rotation stopper portioninto contact with two faces on one side of an outer peripheral face ofthe flange member opposed to each other and bringing the second rotationstopper portion into contact with two faces on other side of the outerperipheral face of the flange member opposed to each other.

[0041] According to a twenty-second aspect of the invention, there isprovided the optical connector according to any one of the nineteenththrough twenty-first aspects, wherein the plug housing and the adapterhousing are provided with engagement restricting portions forrestricting engaging positions in the rotating direction centering onaxes thereof.

[0042] According to the invention, fabrication cost can be reduced andan integrating step can be simplified by reducing a number of parts ofthe optical connector comprising the optical connector plug and theoptical connector adapter. Further, the reliability can be promotedwithout restricting a number of times of attachment and detachment ofthe optical connector plug and the optical connector adapter and withoutdamaging a front end face of the optical fiber. Further, by providingthe mounting member attachable and detachable to and from the opticalconnector adapter at the optical connector, it is not necessary toattach and detach the optical connector adapter and the opticalconnector plug on the mounting board and the mounting board can bedownsized.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043]FIG. 1 is a perspective view showing a step of mounting an opticalconnector according to Embodiment 1 of the invention;

[0044]FIGS. 2A, 2B and 2C are sectional views of the optical connectoraccording to Embodiment 1;

[0045]FIGS. 3A, 3B and 3C are plane views and a sectional view of anoptical connector plug according to Embodiment 1 of the invention;

[0046]FIG. 4 is a plane view showing a step of integrating the opticalconnector plug according to Embodiment 1 of the invention;

[0047]FIGS. 5A, 5B and 5C are a plane view and sectional views of anoptical connector adapter according to Embodiment 1 of the invention;

[0048]FIGS. 6A and 6B are plane views of the optical connector adapteraccording to Embodiment 1 of the invention;

[0049]FIG. 7 is a perspective view showing a step of mounting tolaminate the optical connectors according to Embodiment 1 of theinvention.

[0050]FIG. 8 is a perspective view showing a state of mounting tolaminate the optical connector according to Embodiment 1 of theinvention;

[0051]FIGS. 9A and 9B are a plane view and a sectional view showing astate of mounting to laminate the optical connectors according toEmbodiment 1 of the invention;

[0052]FIG. 10 is a perspective view showing a step of mounting tolaminate optical connectors according to Embodiment 2 of the invention;

[0053]FIG. 11 is a perspective view showing a state of mounting tolaminate the optical connectors according to Embodiment 2 of theinvention;

[0054]FIG. 12 is a perspective view showing a step of integrating anoptical connector adapter according to Embodiment 3 of the invention;

[0055]FIGS. 13A and 13B are a plane view and a sectional view of theoptical connector adapter according to Embodiment 3 of the invention;

[0056]FIG. 14 is a perspective view showing a state of connecting theoptical connector and a plug releasing jig according to Embodiment 3 ofthe invention;

[0057]FIG. 15 is a perspective view showing a step of mounting tolaminate the optical connectors according to Embodiment 3 of theinvention;

[0058]FIG. 16 is a perspective view showing a state of mounting tolaminate the optical connectors and a mount releasing jig according toEmbodiment 3 of the invention; and

[0059]FIG. 17 is a perspective view showing a mounting step showingother example of a mounting member according to other embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060] The invention will be explained in details based on embodimentsas follows.

EMBODIMENT 1

[0061]FIG. 1 is a perspective view showing a step of mounting an opticalconnector according to Embodiment 1, FIG. 2A is a sectional view showinga step of connecting the optical connector, FIG. 2B is a sectional viewshowing a state of connecting the optical connector, FIG. 2C is asectional view taken along a line A-A′ of FIG. 2B, FIGS. 3A and 3B areplane views of an optical connector plug, FIG. 3C is a sectional viewtaken along a line B-B′ of FIG. 3A and FIG. 4 is a plane view showing astep of integrating the optical connector plug.

[0062] As illustrated, an optical connector jig 10 comprises an opticalconnector plug 20, an optical connector adapter 50 and a mounting member70.

[0063] The optical connector plug 20 is constituted by a ferrule 21 forholding an optical fiber 1, a plug housing 23 for directly holding theferrule 21 movably in an axial direction in a predetermined range andprovided with a first rotation stopper portion 22 for restrictingmovement in a-rotating direction, and an urge spring 24 for urging theferrule 21 to a side of a front end face in the axial direction thereof.

[0064] The ferrule 21 includes a ferrule cylindrical member 25 and aflange member 26 provided at a rear end portion of the ferrulecylindrical member 25.

[0065] The ferrule cylindrical member 25 is provided with a cylindricalshape and includes an optical fiber inserting hole 27 capable ofinserting the optical fiber 1 by penetrating in the axial direction atinside thereof. A rear end portion of the optical fiber inserting hole27 is provided with a taper portion 27 a an inner diameter of which isgradually increased to an opening side. By providing such a taperportion 27 a, when the optical fiber 1 is inserted into the opticalfiber inserting hole 27, a front end of the optical fiber 1 can beprevented from being chipped or broken by being brought into contactwith an end face of the ferrule cylindrical member 25.

[0066] Further, as a material of the ferrule cylindrical member 25, forexample, a ceramics material of zirconia or the like, a plasticmaterial, a glass material of crystallized glass, borosilicate glass,quartz or the like, a metal material of stainless steel, nickel or thelike can be pointed out. Further, an outer diameter of the ferrulecylindrical member 25 is set to 1.25 mm according to the embodiment.

[0067] The flange member 26 includes an optical fiber core lineinserting hole 28 communicating with the optical fiber inserting hole 27of the ferrule cylindrical member 25 and capable of inserting an opticalfiber core line 2 having a coating at an outer periphery of the opticalfiber 1. A side of a front end portion of the optical fiber core lineinserting hole 28 constitutes a fitting hole 28 a formed by an innerdiameter of a size substantially equivalent to an outer diameter of theferrule cylindrical member 25 and fixedly attached to a rear end portionof the ferrule cylindrical member 25 by press-fitting or adherence.

[0068] Further, an outer periphery on a side of a front end portion ofthe flange member 26 includes a flange portion 29 projected in arectangular shape over a circumferential direction. The flange portion29 is engaged with a first rotation stopper portion 22 of the plughousing 23 to be mentioned later in details to restrict the movement ofthe ferrule 21 in the rotating direction centering on an axis thereof.

[0069] Further, an inserting portion 30 capable of inserting the urgespring 24 is extended on a rear die of the flange member 26. Theinserting portion 30 is constituted by a small diameter portion 31 anouter diameter of which is comparatively small on a side of a rear endportion thereof and a large diameter portion 32 an outer diameter ofwhich is larger than that of the small diameter portion 31 on a side ofthe flange portion 29.

[0070] An outer periphery of the large diameter portion 32 of theinserting portion 30 is provided with a projection for spring 33engaging with the urge spring 24 by being projected over acircumferential direction thereof.

[0071] Further, an outer periphery of the small diameter portion 31 ofthe inserting portion 30 is provided with an engaging projection 34 anouter diameter of which is substantially equivalent to that of the largediameter portion 32 over a circumferential direction thereof and aninclined taper face 34 a is constituted by a face on a side of a rearend portion of the engaging projection 34. The taper face 34 a providedat the engaging portion 34 is for inserting the inserting portion 30 ofthe flange member 26 into an engaging hole 36 of the plug housing 23,mention later, while pushing to widen the engaging hole 36 in insertingthereinto.

[0072] Further, according to the embodiment, the flange member 26 isformed by a metal of stainless steel or the like. Further, the materialand a method of fabricating the flange member 26 are not particularlylimited thereto but, for example, the flange member 26 may integrally bemolded to a rear end portion of the ferrule cylindrical member 25 byplastic.

[0073] Further, the urge spring 24 of a compression spring or the likeis provided at an outer periphery of the inserting portion 30 of theflange member 26. The urge spring 24 is engaged with the projection forspring 33 provided at the large diameter portion 32 of the insertingportion 30 to thereby temporarily prevent the urge spring 24 from beingdetached from the ferrule 21.

[0074] Meanwhile, the plug housing 23 comprises, for example, plastic orthe like and is provided with a ferrule holding hole 35 for holding theferrule 21 and the urge spring 24 by penetrating in the axial direction.

[0075] A rear end portion of the ferrule holding hole 35 is providedwith the engaging hole 36 having an inner diameter larger than the smalldiameter portion 31 of the flange member 26 and smaller than theengaging projection 34.

[0076] By inserting the small diameter portion 31 of the insertingportion 30 of the flange member 26 into the engaging hole 36, theferrule 21 is held in the plug housing 23 movably in the axial directionby a predetermined amount.

[0077] That is, when the inserting portion 30 of the flange member 26 isinserted into the engaging hole 36, the engaging projection 34 having anouter diameter larger than the engaging hole 36 pushes to widen theengaging hole 36 to elastically deform. When the engaging projection 34has passed through the engaging hole 36, the inner diameter of theengaging hole 36 recovers to the original inner diameter and theengaging projection 34 is brought into contact with the rear end face ofthe plug housing 23 at which the engaging hole 36 is opened to therebyhold the ferrule 21 to the plug housing 23 in a state in which movementthereof on a side of a front end face thereof is restricted.

[0078] Further, The urge spring 24 held at an outer peripheral face ofthe inserting portion 30 of the flange member 26 of the ferrule 21 urgesthe ferrule 21 to a front end side in the axial direction of the plughousing 23 by bringing one end thereof into contact with the flangeportion 29 and bringing other end thereof into contact with an innerface thereof at which the engaging hole 36 is opened.

[0079] Further, as described above, the ferrule 21 urged to the frontend side in the axial direction by the urge spring 24 is held in thestate in which the ferrule 21 is urged to the front end face side byrestricting the movement to the front end side in the axial direction bybringing the engaging projection 34 provided at the flange member 26into contact with the rear end face of the plug housing 23 at which theengaging hole 36 is opened.

[0080] Further, since the engaging hole 36 of the plug housing 23 ispushed to widen to the engaging projection 34 when the inserting portion30 of the flange member 26 is inserted thereinto, two intermittentopening portions 37 are provided at the rear end portion of the plughousing 23 at which the engaging hole 36 is provided over acircumferential direction at a surrounding of the engaging hole 36. Thesurrounding of the engaging hole 36 is liable to be deformed elasticallyby the opening portions 37 and the inserting portion 30 of the flangemember 26 is facilitated to be inserted into the engaging hole 36.

[0081] Further, an outer peripheral face of the plug housing 23 isprovided with as lit for optical fiber 38 for communicating the ferruleholding hole 35 to outside over the axial direction. The slit foroptical fiber 38 is formed by a width larger than diameters of theoptical fiber 1 and the optical fiber core line 2 held by the ferrule 21and more or less smaller than the outer diameter of the small diameterportion 31 of the flange member 26.

[0082] In integrating the optical connector plug 20, the slit foroptical fiber 38 simplifies the integration by attaching the plughousing plug 23 to the ferrule 21 holding the optical fiber land theoptical fiber core line 2 later without previously inserting the opticalfiber 1 and the optical fiber core line 2 into the plug housing 23.

[0083] By providing the slit for optical fiber 38 to the plug housing 23in this way, it is not necessary to previously insert the optical fiber1 into the plug housing 23 and therefore, the yield can be promoted bypreventing the optical fiber 1 from being broken or damaged.

[0084] Further, the plug housing 23 is provided with a pair of clawportions 40 to interpose the ferrule 21 and provided with locking claws39 at inner faces of front end portions thereof opposed to each other.

[0085] The claw portions 40 are for engaging the optical connector plug20 and the optical connector adapter 50 by being engaged with an adapterhousing 52 of the optical connector adapter 50 to be mentioned later indetails.

[0086] Further, regions of the respective claw portions 40 opposed tothe flange portion 29 are respectively provided with the first rotationstopper portions 22 provided to project to be brought into contact withrespectives of the pair of faces of the outer peripheral face of theflange portion 29 opposed to each other.

[0087] The first rotation stopper portions 22 provided at respectives ofthe claw portions 40 are brought into contact with the pair of faces ofthe outer peripheral face of the flange portion 29 opposed to eachother, that is, by interposing the flange portion 29 by the firstrotation stopper portions 22 provided at the pair of claw portions 40,movement of the ferrule 21 in the rotating direction centering on theaxis is restricted relative to the plug housing 23.

[0088] Further, the pair of claw portions 40 are formed at an intervalby which inner faces thereof opposed to each other on a side of the rearend portion of the first rotation stopper portion 22 is not brought intocontact with the flange portion 29 when the flange portion 29 isrotated.

[0089] That is, when the ferrule 21 of the optical connector plug 20 ispressed to the side of the rear end portion in the axial directionagainst urge force of the urge spring 24, engagement between the firstrotation stopper portion 22 and the flange portions 29 is disengaged andthe ferrule 21 can be rotated relative to the plug housing 23. Thereby,even after integrating the ferrule 21 and the plug housing 23,positioning of the ferrule 21 in the rotating direction can be carriedout by an eccentric direction of the optical fiber 1, and insertion losscan be reduced by matching eccentric directions of the optical connectorplugs 20 when the optical connector plugs 20 are opposedly connected bythe optical connector adapter 50 to be mentioned later in details.

[0090] Further, according to the embodiment, a groove portion 41 havinga predetermined depth is formed at a front end face of the flangeportion 29 and the ferrule 21 may be pressed to the rear end portionside and rotate in a pressed state by a jig engaged with the grooveportion 41, although not particularly illustrated.

[0091] Further, as shown by FIG. 1, one of edge portions of one of theclaw portions 40 is provided with an engagement restricting portion 42to be engaged with an engagement restricting recess portion 63 a of theoptical connector adapter 50, mentioned later.

[0092] By providing the engagement restricting portion 42 only at one ofthe edge portions of one of the claw portions 40, the engagementrestricting portion 42 can restrict a position of engaging the opticalconnector plug 20 to the optical connector adapter 50 in the rotatingdirection centering on the axis. That is, when the optical connectorplug 20 is engaged with the optical connector adapter 50, the opticalconnector plug 20 and the optical connector 50 can be engaged with eachother always at the same rotating position. Thereby, when the opticalconnector plugs 20 are opposedly connected, eccentric directions of theoptical fibers 1 are not different from each other and the insertionloss can be prevented from increasing.

[0093] As a method of integrating the optical connector plug 20, first,the ferrule 21 is formed by fixing the flange member 26 to the rear endportion of the ferrule cylindrical member 25 by press-fitting. Next, byinserting the inserting portion 30 of the flange member 26 into the urgespring 24, the urge spring 24 is engaged with the projection for spring33 provided on the large diameter portion 32 and the urge spring 24 istackedly fixed to the outer peripheral face of the inserting portion 30.

[0094] Next, the ferrule 21 tackedly fixed with the urge spring 24 isadhered with the optical fiber 1 and the optical fiber core line 2 via athermosetting type adhering agent. A front end face of the ferrule 21holding the optical fiber 1 and the optical fiber core line 2 in thisway is polished by a polishing apparatus or the like along with a frontend face of the optical fiber 1.

[0095] Thereafter, as shown by FIG. 4, the optical fiber core line 2held by the ferrule 21 is inserted into the slit for optical fiber 38 ofthe plug housing 23 and the inserting portion 30 of the flange member 26is inserted into the engaging hole 36 of the plug housing 23. At thisoccasion, the inserting portion 30 is inserted into the engaging hole 36while pressing to widen the engaging hole 36 by the engaging projection34 and the engaging projection 34 is engaged with the engaging hole 36in the state in which movement to the front end side is restricted.

[0096] Thereby, the optical connector plug 20 according to theembodiment can be constituted by holding the ferrule 21 movably in theaxial direction by a predetermined amount in the ferrule holding hole 35of the plug housing 23 in the state in which the ferrule 21 is urged tothe front end side in the axial direction and the movement in therotating direction centering on the axis is restricted by the firstrotation stopper portions 22 of the claw portions 40.

[0097] Since the optical connector plug 20 is constituted only by theferrule 21, the urge spring 24 and the plug housing 23 in this way,fabrication cost can be reduced by reducing a number of parts. Further,a procedure of integrating the optical connector plug 20 can besimplified since the urge spring 24 can tackedly be fixed to the rearend portion of the ferrule 21 and the plug housing 23 can be fixed tothe ferrule 21 after fixing the optical fiber 1 to the ferrule 21.

[0098] Further, a comparison of dimensions and numbers of parts betweenthe optical connector plug 20 having such a constitution and the MU typeoptical connector plug (JIS C5983F14 type optical connector) of therelated art is shown in Table 1 shown below.

(Table 1)

[0099] embodiment 1 related art total length (mm) 12.8 35 width (mm) 4.56.6 height (mm) 3.6 4.35 number of parts 4 7

[0100] As shown by Table 1, a number of parts of the optical connectorplug 20 of Embodiment 1 is smaller than that of the MU type opticalconnector plug of the related art and all of the total length, the widthand the height can be downsized. Thereby, downsizing of the opticalconnector 10 using the optical connector plug 20 can be achieved andwhen the optical connector 10 is mounted to a mounting board, highdensity formation can be achieved.

[0101] Further, the optical connector 10 using the optical connectorplug 20 optically connects the optical fiber core lines 2 provided withcoatings at outer peripheries of the optical fibers 1 above a mountingboard 100 and therefore, it is not necessary to use an optical fibercable provided with a tension member and a coating at the-outerperiphery of the optical fiber core line 2 and downsizing can be carriedout also thereby.

[0102] Next, the optical connector adapter 50 of the optical connector10 will be explained in details.

[0103]FIG. 5A is a plane view from a side of a bottom face of theoptical connector adapter, FIG. 5B is a sectional view taken along aline C-C′ of FIG. 5A, FIG. 5C is a sectional view taken along a lineD-D′ of FIG. 5A and FIGS. 6A and 6B are plane views from a side of anend face and a side of an upper face of the optical connector adapter.

[0104] As shown by FIGS. 5A, 5B and 5C, the optical connector adapter 50is constituted by a sleeve for optical connection 51 inserted with thefront end portion of the ferrule cylindrical member 25 and the adapterhousing 52 including the sleeve for optical connection 51.

[0105] The sleeve for optical connection 51 is provided with acylindrical shape and includes a ferrule inserting hole 53 provided bypenetrating in an axial direction thereof and a streak of slit 53 aprovided from one end side to other end side in the longitudinaldirection. Further, the ferrule inserting hole 53 is formed by an innerdiameter more or less smaller than an outer diameter of the cylindricalmember for ferrule 25.

[0106] Optical connection is carried out by respectively inserting frontend portions of the cylindrical members for ferrule 25 from openings onboth sides of the ferrule inserting hole 53 of the sleeve for opticalconnection 51. At this occasion, the sleeve for optical connection 51 iselastically deformed in a direction of expanding the slit 53 a byinserting the front end portions of the cylindrical members for ferrule25 and therefore, the front end portions of the cylindrical members forferrule 25 can opposedly be connected by being brought into closecontact with the inner face of the ferrule inserting hole 53 to hold.

[0107] Further, as a material of the sleeve for optical connection 51,for example, a ceramic material of zirconia or the like or a metalmaterial of copper alloy or the like can be pointed out.

[0108] Further, the adapter housing 52 is formed by, for example,integrally molding a resin of plastic or the like and is provided with athrough hole 54 for holding the sleeve for optical connection 51 bypenetrating in the axial direction.

[0109] The cylindrical members for ferrule 25 are inserted from the bothend sides of the through hole 54 to be inserted into the sleeve foroptical connection 51 held in the through hole 54.

[0110] That is, the through hole 54 is provided with a sleeve holdingportion 55 having a diameter more or less larger than the outer diameterof the sleeve for optical connection 51 substantially on a central sidethereof and communication holes 56 each having an inner diametersubstantially equivalent to the outer diameter of the cylindrical memberfor ferrule 25 on both end sides of the sleeve holding portion 55 and astepped difference portion 57 is provided by a difference between innerdiameters of these.

[0111] By bringing both end faces of the sleeves for optical connection51 in contact with the stepped difference portions 57, the sleeve foroptical connection 51 is held by the sleeve holding portion 55 in astate in which movement thereof in the axial direction is restricted.

[0112] Further, the adapter housing 52 is provided with a sleeveinserting hole 58 formed by a size equivalent to that of the sleeveholding portion 55 for communicating the sleeve holding portion 55 tooutside and the sleeve for optical connection 51 is inserted into thesleeve holding portion 55 from the sleeve inserting hole 58.

[0113] Further, inner side faces of the sleeve inserting hole 58 opposedto each other are provided with two pairs of projections for sleeve 59to be opposed to each other which are provided to project such thatwidths thereof are narrower than that of the sleeve holding portion 55.The projection for sleeve 59 is provided in a taper shape such that anamount of projection thereof is reduced to an opening side of the sleeveinserting hole 58. The sleeve for optical connection 51 inserted fromthe sleeve inserting hole 58 is inserted into the sleeve holding portion55 by pressing to widen the two pairs or projections for sleeve 59 andthe projections for sleeve 59 are brought into contact with an outerperipheral face of the inserted sleeve for optical connection 51,thereby, the sleeve for optical connection 51 is held in the sleeveholding portion 55 in a state in which movement in a radius directionthereof is restricted.

[0114] Further, as shown by FIG. 1 and FIGS. 2A and 2B, at theperipheries of the both end portions of the adapter housing 52, engagingrecess portions 60 for engaging with the pair of claw portions 40 of theoptical connector plug 20 are provided at respective opposed facesthereof.

[0115] The engaging recess portions 60 are formed from both end faces ofthe adapter housing 52 such that lengths and thickness thereof aresubstantially equivalent to those of the claw portions 40 and a bottomface of the engaging recess portion 60 is provided with an engagingprojection portion 61 projected to a side of an opening face of theengaging recess portion 60. A taper face 61 a is formed at a face of theengaging projection portion 61 on a side thereof inserted with the clawportion 40. When the claw portions 40 are inserted into the engagementrecess portions 60 from sides of end faces thereof, an interval betweenthe pair of claw portions 40 is pressed to widen by elasticallydeforming the claw portions 40 by bringing the locking claws 39 intocontact with the taper faces 61 a of the engaging projection portions 61and the locking claws 39 passing the engaging projection portions 61 areengaged with the engaging projection portions 61 to there by engage theoptical connector plug 20 and the optical connector adapter 50.

[0116] Further, both end faces of the adapter housing 52 are providedwith second rotation stopper portions 62 for restricting movement in therotating direction of the ferrule 21 centering on the axis by beingengaged with the flange portions 29 of the flange member 26.

[0117] The second rotation stopper portions 62 are formed as acommunicating hole in a rectangular shape communicating with thecommunication hole 56 of the through hole 54 and having a size ofinserting the flange portions 29 of the flange member 26 and notchportions 63 are formed on sides thereof of the engaging recess portions60 inserted with the flange portions 29 of the second rotation stopperportion 62. That is, the movement in the rotating direction centering onthe axis of the ferrule 21 is restricted by bringing the first rotationstopper portions 22 provided at the claw portions 40 into contact withones of the outer peripheral faces of the flange portions 29 opposed toeach other and bringing the second rotation stopper portions 62 intoothers of the outer peripheral faces of the flange portions 29 opposedto each other.

[0118] That is, the movement in the rotating direction centering on theaxis of the ferrule 21 is restricted by engaging the optical connectorplug 20 and the optical connector adapter 50 by the claw portions 40 andthe engaging recess portions 60.

[0119] As shown by FIG. 1 and FIGS. 6A and 6B, one of the edge portionsof one of the notch portions 63 is provided with the engagementrestricting recess portion 63 a to be inserted with the engagementrestricting portion 42 of the optical connector plug 20.

[0120] The engaging restricting recess portion 63 a restricts anengaging position in the rotating direction centering on the axis of theoptical connector plug 20 by being provided at one of the edge portionsof one of the notch portions 63.

[0121] An explanation will be given here of optical connection of theoptical connector plugs 20.

[0122] As shown by FIG. 2A, one of the optical connector plugs 20 isinserted to one end side of the optical connector adapter 50 to hold.

[0123] In details, the claw portions 40 of the optical connector plug 20are engaged with the engaging recess portions 60 of the opticalconnector adapter 50. At this occasion, the optical connector plug 20 isprovided with the engagement restricting portion 42 only at one of theedge portions of the one of the claw portions 40 and therefore, the clawportions 40 are engaged with the engagement recess portions 60 such thatthe engagement restricting portion 42 is inserted into the engagementrestricting recess portion 63 a of the optical connector adapter 50.

[0124] Thereby, the engaging position in the rotating direction of theoptical connector plug 20 can be positioned relative to the opticalconnector adapter 50.

[0125] Further, the ferrule 21 held between the optical connectoradapter 50 and the optical connector plug 20 which are engaged is heldin a state in which movement in the rotating direction centering on theaxis is restricted by the first rotation stopper portions 22 and thesecond rotation stopper portions 62.

[0126] The ferrule 21 is urged to be held in a state in which movementon the front end side is restricted by bringing the engaging projection34 of the inserting portion into contact with the engaging hole 36 andsuch that movement thereof to the rear end side by pressing can becarried out.

[0127] Next, as shown by FIG. 2B, other of the optical connector plug 20is inserted into other end side of the optical connector adapter 50 tohold.

[0128] Also the engagement between the optical connector adapter 50 andthe optical connector plug 20 is carried out by engaging the clawportions 40 and the engagement recess portions 60 similar to the oneoptical connector plug 20 and the optical connector adapter 50,mentioned above.

[0129] When the other optical connector plug 20 is engaged with theoptical connector adapter 50 in this way, by bringing the front endfaces of the ferrules 21 into contact with each other, the ferrules 21are moved to rear end portion sides against urge force of the urgesprings 24.

[0130] In this way, optical connection can be carried out by bringingthe ferrules 21 into contact with each other in the state in which thefront end faces of the ferrules 21 urged to the front end portion sidesby the urge force of the urge springs 24 are pressed by predeterminedpressure.

[0131] In this way, the optical connector plug 20 and the opticalconnector adapter 50 can be attached to each other and detached fromeach other by any times by optically connecting the optical connectorplugs 20 via the optical connector adapter 50.

[0132] Further, the movement of the ferrule 21 in the rotating directionis restricted by the second rotation stopper portion 62 and therefore,the ferrule 21 is not inserted into the sleeve for optical connection 51in a skewed direction and the front end face of the ferrule 21 isdifficult to be damaged. Thereby, not only the insertion loss in opticalconnection can be reduced but also the reliability can be promoted.

[0133] Further, in disengaging the engagement between the opticalconnector plug 20 and the optical connector adapter 50, the engagementmay be disengaged by widening the claw portions 40 of the opticalconnector plug 20 by a jig although not particularly illustrated.

[0134] Further, one face of the adapter housing 52 is provided with amount engaging portion 64 for engaging with the mounting member 70.

[0135] According to the embodiment, the mount engaging portions 64 areprovided as projections projected at four locations at a face of theadapter housing 52 on the side of the sleeve inserting hole 58 and anengaging groove 64 a is formed on the inner face side of the mountengaging portion 64.

[0136] Further, as shown by FIG. 6A and 6B, other face of the adapterhousing 52 is provided with a projection for lamination 65 and anengaging portion for lamination 66 having shapes equivalent to those ofa projection for adapter 76 and an engaging portion for adapter 77 ofthe mounting member 70 used in attachment and detachment to and from theadapter housing 52 which will be described later in details.

[0137] The projection for lamination 65 and the engaging portion forlamination 66 are for laminating a plurality of the optical connectors10 by engaging with the adapter housing of other optical connectoradapter attachably and detachably thereto and therefrom although detailsthereof will be described later.

[0138] Since the optical connector adapter 50 is constituted by thesleeve for optical connection 51 and the integrally molded adapterhousing 52, the cost can be reduced by reducing the number of parts.

[0139] A comparison of dimensions and numbers of parts between theoptical connector adapter 50 constituted in this way and the MU typeoptical connector adapter (JIS C5983 F14 type optical connector) of therelated art is shown in Table 2 shown below. TABLE 2 embodiment 1related art total length (mm) 13.6 26 width (mm) 4.5 10.4 height (mm)4.0 7.5 number of parts 2 5

[0140] As shown by Table 2, a number of parts of the optical connectoradapter 50 according to the embodiment is smaller than that of the MUtype optical connector adapter of the related art and all of the totallength, the width and height can be downsized. Thereby, downsizing ofthe optical connector 10 using the optical connector adapter 50 can bedownsized and the high density formation can be achieved when theoptical connector 10 is mounted to a mounting board.

[0141] Next, the mounting member 70 will be described in details.

[0142] As shown by FIG. 1 and FIG. 2C, the mounting member 70 isconstituted by fixing portions 71 of bent both end portions having achannel-like shape formed by bending both end portions of a member in ashape of a flat plate and a base seat portion 72 at a region between thetwo mixing portions 71.

[0143] The fixing portion 71 is inserted into a fixing hole 101 providedto penetrate the mounting board 100 to hold and a front end portionthereof is constituted by a stepped difference portion 73 a width ofwhich is wider than that of the side of the base seat portion 72 andwider than an inner diameter of the fixing hole 101.

[0144] Further, a front end face of the fixing portion 71 is formed by ataper face 74 to facilitate to be inserted into the fixing hole 101 anda notch portion 75 notched by a predetermined amount in a longitudinalfrom the front end is provided at substantially a central portionthereof in the width direction.

[0145] When the fixing portion 71 is inserted into the fixing hole 101of the mounting board 100, the fixing portion 71 is inserted into thefixing hole 101 by bringing an edge portion of the fixing portion 71into contact with the taper face 74 of the fixing portion 71 andelastically deforming the fixing portion 71 to narrow the width of thenotch portion 75.

[0146] Further, the inserted fixing portion 71 is held by preventing themounting member 70 from drawing from the fixing hole 101 by bringing thestepped difference portion 73 into contact with an opening edge portionof the fixing hole 101.

[0147] Further, the base seat portion 72 of the mounting member 70 isprovided with a pair of projections for adapter 76 projected into thesleeve inserting hole 58 of the adapter housing 52 by being projected toa side opposed to the fixing portion 71 substantially at a centralportion thereof and four adapter engaging portions 77 engaged withrespectives of the engaging grooves 64 a of the four mount engagingportions 64 of the adapter housing 52 at edge portions in the widthdirection of the base seat portion 72.

[0148] The projections for adapter 76 are provided to project to sidesof both ends in the longitudinal direction of the sleeve inserting hole58 of the adapter housing 52 and by bringing the projections for adapter76 into contact with the both ends in the longitudinal direction of thesleeve inserting hole 58, movement of the adapter housing 52 in theaxial direction of the optical fiber 1 is restricted relative to themounting member 70.

[0149] Further, the adapter engaging portion 77 is formed to beprojected to be inclined to the width to the width direction of the baseseat portion 72 and by engaging the adapter engaging portion 77 to theengaging groove 64 a of the mount engaging portion 64, the adapterengaging portion 77 is held by restricting movement of the adapterhousing 52 in the width direction and the attaching and detachingdirection relative to the mounting member 70 of the adapter housing 52.

[0150] That is, when a face of the adapter housing 52 provided with thesleeve inserting hole 58 is brought into contact with the base seatportion 72 of the mounting member 70, the adapter engaging portion 77 ofthe mounting member 70 is engaged with the mount engaging portion 64 ofthe adapter housing 52, the movement in the width direction and theattaching and detaching direction is restricted, the pair of projectionsfor adapter 76 provided at the base seat portion 72 are projected intothe sleeve inserting hole 58 of the adapter housing 52, thereby, theadapter housing 52 is held by restricting the movement in thelongitudinal direction.

[0151] Further, since the inner faces of the engaging grooves 64 a ofthe mount engaging portions 64 are formed by the inclined faces and theadapter engaging portions 77 are formed to be inclined, the mountingmember 70 and the optical connector adapter 50 can be attached anddetached to and from each other by being pressed or drawn bypredetermined force.

[0152] Such a mounting member 70 can be formed by, for example, metalpressing.

[0153] As a method of integrating the optical connector constituted bythe optical connector plug, the optical connector adapter and themounting member, first, the mounting member 70 is fixed to the mountingboard 100. Next, the optical connector plugs 20 are fixed to the bothsides of the optical connector adapter 50 to thereby optically connectthe optical connector plugs 20. Thereafter, by fixing the opticalconnector adapter 50 fixed with the optical connector plugs 20 to themounting member 70, the optical connector 10 optically connecting theoptical fibers 1 can be mounted to the mounting board 100.

[0154] Further, in order to disengage the optical connector plug of theoptical connector mounted to the mounting board 100 in this way, theoptical connector plug 20 may be disengaged from the optical connectoradapter 50 after disengaging theoptical connector adapter 50 fixed withthe optical connector plugs 20 from the mounting member 70.

[0155] By making the mounting member attachable and detachable to andfrom the optical connector adapter 50, the optical connector adapter 50can be attached and detached thereto and therefrom after fixing themounting member 70 to the mounting board 100 and therefore, it is notnecessary to engage the optical connector adapter 50 and the opticalconnector plug 20 on the mounting board 100 and it is not necessary toprovide a space for attaching and detaching the optical connectoradapter 50 to and from the optical connector plug 20 at the mountingboard 100. Thereby, not only the mounting board 100 can be downsized butalso mounting of the optical connector 10 can easily be carried out.

[0156] Here, FIG. 7 is a perspective view showing a step of mounting tolaminate optical connectors, FIG. 8 is a perspective view showing astate of mounting to laminate optical connectors and FIGS. 9A and 9B area plane view showing a state of mounting to laminate optical connectorsand a sectional view taken along a line E-E′ thereof.

[0157] The projection for lamination 65 and the engaging portion forlamination 66 are provided at a face of the adapter housing 52 of theoptical connector adapter 50 on a side opposed to the mount engagingportion 64.

[0158] As shown by FIGS. 5A, 5B and 5C and FIGS. 6A and 6B, theprojection for lamination 65 is provided with a shape equivalent to thatof the projection for adapter 76 of the mounting member 70 and projectedinto the sleeve inserting hole 58 of other of the optical connectoradapter 50 to thereby prevent the other optical connector adapter 50from moving in the longitudinal direction relative to the opticalconnector adapter 50.

[0159] Further, the engaging portion for lamination 66 is formed toproject by forming the groove along an outer peripheral edge portion tobe engaged with the mount engaging portion 64 of the other opticalconnector adapter 50. By engaging the engaging portion for lamination 66with the mount engaging portion 64 of the other optical connectoradapter 50, the other optical connector adapter is held attachably anddetachably to and from the optical connector adapter 50.

[0160] By providing the projection for lamination 65 and the engagingportion for lamination 66 for engaging with the optical connectoradapter 50 at the face of the optical connector adapter 50 on the sideopposed to the mount engaging portion 64 in this way, a plurality of theoptical connector adapters 50 can be laminated, it is not necessary toalign a plurality of the optical connectors 10 on the mounting board 100in the face direction and downsizing can be achieved by narrowing themounting area of the mounting board 100.

[0161] Here, a comparison of the total lengths and mounting densities ofthe optical connector 10 according to Embodiment 1 and the MU typeoptical connector plug (JIS C5983 F14 type optical connector) of therelated art is shown in Table 3, shown below. Further, the mountingdensity shown in Table 3, shown below, is constituted by fixing theoptical connector plugs 20 on the both sides of the optical connectoradapter and is a relative value by constituting a reference by the MUtype optical connector of the related art.

(Table 3)

[0162] related art embodiment 1 (nonpatent literature 1) total length1/3 1 mounting density 2 or more 1 (width direction) mounting density 21 (height direction)

[0163] As shown by Table 3, according to the optical connector 10 of theembodiment, the mounting density twice or more as much as that of the MUtype optical connector plug of the related art in the width directionand the mounting density twice as much as that of the MU type opticalconnector plug of the related art in the height direction can berealized. Further, since the total length of the optical connector 10 ofthe embodiment can be made ⅓ of that of the MU type optical connector ofrelated art, also the mounting density in the longitudinal direction ofthe embodiment can be three times as much as that of the MU type opticalconnector of the related art. Further, in the longitudinal direction,engagement and disengagement of the optical connector plug 20 and theoptical connector adapter 50 can be carried out by a narrow area andtherefore, a substantial mounting density of the embodiment can be madethree times as much as that of the MU type optical connector of therelated art.

EMBODIMENT 2

[0164]FIG. 10 is a perspective view showing a step of mounting tolaminate optical connectors according to Embodiment 2 and FIG. 11 is aperspective showing a state of mounting to laminate optical connectersaccording to Embodiment 2. Further, members similar to those ofEmbodiment 1, mentioned above, are attached with the same notations andduplicated explanation thereof will be omitted.

[0165] As shown by FIG. 10 and FIG. 11, an optical connector 10A isprovided with the optical connector plug 20, an optical connectoradapter 50A and a mounting member 70A.

[0166] The mounting member 70A comprises the bent portion 71 and a baseseat portion 72A and adapter engaging portions 77A are provided at edgeportions on both sides in a width direction of the base seat portion72A.

[0167] The adapter engaging portions 77A are formed to bend to projectto a side opposed to the bent portion 71 and formed such that front endportions thereof are bent to both sides in the width direction toconstitute directions the same as directions of the face of the baseseat portion 72A.

[0168] An adapter housing 52A of the optical connector adapter 50Aengaged with the mounting member 70A is provided with a mount engagingportion 64A projected to a side of the sleeve inserting hole 58.

[0169] The mount engaging portion 64A is provided to project to the sideof the mounting member 70A and a front end portion thereof is formed ina shape projected to an inner side.

[0170] The optical connector adapter 50A and the mounting member 70A canengage the mount engaging portion 64A and the adapter engaging portion77A by sliding to move in a state in which a face of the adapter housing52A on the side of the sleeve inserting hole 58 is brought into contactwith the base seat portion 72A of the mounting member 70A.

[0171] Further, a face of the mount engaging portion 64A of the adapterhousing 52A on a side opposed to the mount engaging portion 64A isprovided with a lamination engaging portion 66A in a groove-like shapeto be engaged with the mount engaging portion 64A of other of theoptical connector adapter 50A.

[0172] The optical connectors 10A can be mounted to laminate on themounting board 100 by attachably and detachably laminating a pluralityof the optical connector adapters 50A by the lamination engagingportions 66A.

[0173] In this way, according to the embodiment, the optical connectoradapter 50A is moved to slide to engage with the mounting member 70A tothereby make the optical connector adapter 50A and the mounting member70A attachable and detachable to and from each other and thereby,similar to Embodiment 1, mentioned above, attachment and detachment ofthe optical connector adapter 50A to and from the optical connector plug20A can be facilitated to execute and the mounting board 100 can bedownsized.

EMBODIMENT 3

[0174]FIG. 12 is a perspective view showing a step of integrating anoptical connector adapter according to Embodiment 3 and FIGS. 13A and13B are a plane view of the optical connector adapter and a sectionalview taken along a line F-F′ thereof. Further, members similar to thoseof Embodiments land 2, mentioned above, are attached with the samenotations and a duplicated explanation thereof will be omitted.

[0175] As shown by FIG. 12 and FIGS. 13A and 13B, an optical connectoradapter 50B of the embodiment is provided with the sleeve for opticalconnection 51 inserted with a front end portion of a cylindrical memberfor ferrule and an adapter housing 52B including the sleeve for opticalconnection 51 and an adapter housing 52B and is constituted by a housingmain body 110 provided with a sleeve inserting hole 58B inserted withthe sleeve for optical connection 51 and opened at one face thereof anda lid member 120 fitted to the sleeve inserting hole 58B of the housingmain body 110.

[0176] The housing main body 110 is formed by, for example, integrallymolding a resin of plastic or the like and is provided with the throughhole 54 penetrated in the axial direction similar to Embodiment 1,mentioned above.

[0177] The through hole 54 includes a sleeve holding portion (notillustrated) holding the sleeve for optical connection 51 substantiallyon the central side and the through holes 56 inserted with thecylindrical members for ferrule on sides of both ends of the sleeveholding portion and a stepped difference portion (not illustrated) isprovided by a difference between inner diameters of the sleeve holdingportion and the through hole 56.

[0178] Further, the housing main body 110 is provided with the sleeveinserting hole 58B formed by a size substantially equivalent to thesleeve holding hole for communicating the sleeve holding hole andoutside at the one face. A portion of an opening side of the sleeveinserting hole 58B constitutes a fitting portion 111 larger than thesleeve holding portion such that the lid member 120 is fitted theretoand the fitted lid member 120 is not inserted up to the sleeve holdingportion and there is provided a stepped difference portion for lid 112brought into contact with the lid member 120 by the fitting portion 111for restricting movement of the sleeve holding portion of the lid member120 to the sleeve holding portion.

[0179] Further, a pair of fixing recess portions 113 for engaging withfixing projections 122 of the lid member 120 at side faces thereofopposed to each other are provided at inner faces of the fittingportions 111 of the housing member 110.

[0180] Further, two side faces of the housing main body 110 are providedwith recess portions for insertion 114 into which mount engagingportions 64B of the lid member 120 are inserted to guide when the lidmember 120 is fitted to the fitting portion 111 which will be describedlater in details.

[0181] Further, the housing main body 110 is provided with a plugreleasing insertion hole 115 to be inserted with a plug releasing jig,mentioned later in details, at a region in correspondence with thelocking claw 39 of the claw portion 40 of the optical connector plug 20when the housing main body 110 is engaged with the optical connectorplug 20 of Embodiment 1, mentioned above.

[0182] The plug releasing insertion hole 115 is opened to the steppeddifference portion for lid 112 provided by the fitting, portion 111 andis not closed when the lid member 120 is fitted to the fitting portion111.

[0183] Meanwhile, the lid member 120 is formed by, for example,integrally molding a resin of plastic or the like similar to the housingmain body 110 and is constituted by a lid portion 121 fitted to thefitting portion 111 and brought into contact with the stepped differenceportion for lid 112 and is constituted by the mount engaging portion 64Bprojected from a side of the face opposed to a face provided with thefitting portion 111 of the housing main body 110.

[0184] The lid portion 121 is provided with fixing projection portions122 respectively projected into the pair of fixing recess portions 113when the lid portion 121 is fitted to the fitting portion 111 of thehousing main body 110.

[0185] Further, the lid portion 121 is provided with a projection forlamination 65B engaged with the mount engaging portion 64B of other ofthe optical connector adapter 50B.

[0186] The lid portion 121 is provided to project with the pair of mountengaging portions 64B integrally formed therewith from a bottom faceside. The mount engaging portion 64B is provided to project by apredetermined amount from a face opposed to a face of the housing mainbody 110 provided with the fitting portion 111 by being inserted intothe insertion recess portion 114 of the housing main body 110 when thelid member 120 is fitted to the fitting portion 111 of the housing mainbody 110.

[0187] At inner faces of front end portions of the pair of mountengaging portions 64B opposed to each other, there are provided mountengaging projections 113 to be engaged with a mounting member or otherof the adapter holding 52B.

[0188] Further, the lid portion 121 is provided with jig inserting holes124 for inserting a mount engagement releasing jig having a shape of apin for releasing engagement between the mount engaging portion 64B andthe mounting member or other of the adapter housing 52B, described laterin details in correspondence with respectives of the pair of mountengaging portions 64B.

[0189] The jig inserting hole 124 is arranged on the inner face side ofeach of the mount engaging portions 64B and the inner face of the mountengaging portion 64B is provided with a recess portion for inserting jig125 to be inserted with mount engagement releasing jig continuous to theinserting hole 123.

[0190] A taper face 125 a is constituted on a side of a front endportion of the mount engaging portion 64B of the jig inserting recessportion 125 of the mount engaging portion 64B and when the mountengagement releasing jig is inserted into the jig inserting hole 124 ofthe lid member 120, a front end of the mount engagement releasing jig isbrought into contact with the taper face 125 a of the jig insertionrecess portion 125, the taper face 125 a is pushed to widen by pushingthe mount engagement releasing jig further and the mount engagingportions 64B are elastically deformed in directions remote from eachother.

[0191] Further, the recess portion for insertion 114 of the housing mainbody 110 to be fitted with the lid member 120 is provided with a jigguiding recess portion 115 to be inserted with a front end of the mountengagement releasing jig inserted into the jig inserting hole 124 andthe mount engagement releasing jig is guided by the jig guiding recessportion 115.

[0192] According to the optical connector adapter 50B having such aconstitution, since the mount engaging portion 64B provided at the lidmember 120 fitted with one face of the housing main body 110 is providedto project from other face of the housing member 110, the mount engagingportion 64B can be prolonged to facilitate elastic deformation.Therefore, the mount engaging portion 64B can be prevented from beingcracked or broken in engaging and disengaging the optical connectoradapter 50B to and from the mounting member or other of the opticalconnector adapter 50B by the mount engaging portion 64.

[0193] Here, the optical connector 10B using the optical connectoradapter 50B will be explained. Further, FIG. 14 is a perspective viewshowing a state of connecting the optical connector according toEmbodiment 3 and the plug releasing jig.

[0194] Here, the optical connector plug 20 used in the optical connector10B along with the optical connector adapter 50B of the embodiment issimilar to that of Embodiment 1, mentioned above, and therefore, aduplicated explanation thereof will be omitted.

[0195] As shown by FIG. 14, the optical connector plug 20 and theoptical connector adapter 50B of the optical connector 10B are engagedwith each other similar to Embodiment 1, mentioned above.

[0196] Further, the engagement is released by the adapter releasing jig200.

[0197] Here, the adapter releasing jig 200 is provided with releasingportions 201 comprising a shape of a pair of flat plates inserted intothe plug releasing inserting holes 115 of the adapter housing 52B at afront end thereof and a front end of the releasing portion 201constitutes a taper portion 202 a thickness of which is graduallyreduced.

[0198] When the releasing portions 201 having the taper portions 202 areinserted into the plug releasing inserting holes 115, the releasingportions 201 are interposed between the locking claws 39 and the adapterhousing 52B while pushing to widen to elastically deform the clawportions 40 of the optical connector plug 20 to therebyrelease-engagement between the optical connector plug 20 and the opticalconnector adapter 50B.

[0199] Further, an explanation will be given of mounting the opticalconnector 10B to a mounting board.

[0200]FIG. 15 is a perspective view showing a step of mounting tolaminate the optical connector according to Embodiment 3 and FIG. 16 isa perspective view showing a state of mounting to laminate the opticalconnector according to Embodiment 3 and the mounting releasing jig.Further, members similar to those of Embodiments 1 and 2, mentionedabove, are attached with the same notations and a duplicated explanationthereof will be omitted.

[0201] As shown by FIG. 15, a mounting member 70B to be mounted on themounting board 100 is constituted by fixing portions 71 at the two bentend portions and a base seat portion 72B at a region between the twofixing portions 71.

[0202] The base seat portion 72B is provided with an adapter engagingportion 77B with which the mount engaging portion 64B of the opticalconnector adapter 50B is engaged and projections for adapter 76B on bothsides of the adapter engaging portion 77B.

[0203] By bringing the projections for adapter 76B into contact with themount engaging portions 64B engaged with the adapter engaging portion77B, the optical connector 10B is restricted from moving in the axialdirection of the optical fiber 1 relative to the mounting member 70B.

[0204] The optical connector 10B is fixed attachably and detachably toand from the mounting member 70B via the mount engaging portions 64B.

[0205] Further, other of the optical connector 10B is laminated on theoptical connector 10B fixed to the mounting member 70B via the mountengaging portions 64B.

[0206] In details, the optical connector 10B is laminated with other ofthe optical connector 10B by engaging the mount engaging portions 64B ofthe other optical connector 10B with the projections for lamination 65Bprovided at the lid member 120 of the optical connector 10B on themounting member 70B.

[0207] Further, engagement of the laminated optical connectors 10B andengagement of the optical connector 10B with the mounting member 70B canbe released by the mount releasing jig 210 shown in FIG. 16.

[0208] The mount releasing jig 210 is provided with the pair ofreleasing portions 211 each having a shape of a pin inserted into thejig inserting holes 114 of the adapter housing 52B at a front endthereof.

[0209] When the releasing portions 211 of the mount releasing jig 210are inserted into the jig inserting holes 124, as described above, thefront ends of the releasing portions 210 push to open to elasticallydeform the mount engaging portions 64B and engagement of the opticalconnectors 10B or the optical connector 10B and the mounting member 70Bis released.

[0210] In this way, the optical connector 10B of the embodiment can bedownsized by reducing a number of parts and since the number of parts isreduced, releasing of the engagement between the optical connector plug20 and the optical connector adapter 50B as well as releasing ofengagement between the optical connectors 10B or between the opticalconnector 10B and the mounting member 70B can easily be carried out byusing the adapter releasing jig 200 or the mount releasing jig 210.Further, according to the optical connector 10B mounted to the mountingboard 100, releasing of engagement between the optical connector plug 20and the optical connector adapter 50B as well as releasing of engagementbetween the optical connectors 10B or the optical connector 10B and themounting member 70B are not carried out so frequently and therefore, thereleasing is not troublesome even by the adapter releasing jig 200 orthe mount releasing jig 210.

Other Embodiment

[0211] Although the invention has been explained by Embodiments 1through 3 as described above, the optical connector of the invention isnot limited to the above-described.

[0212] For example, according to Embodiments 1 through 3, mentionedabove, the shape of the flange portion 29 and the shapes of the firstrotation stopper portion 22 and the second rotation stopper portion 62for restricting movement of the ferrule 21 in the rotating directioncentering on the axis are not limited to those of Embodiments 1 through3, mentioned above, for example, there may be constructed a constitutionin which the flange portion is formed in a shape of a circular disk andprovided with key grooves over the axial direction at four locationsuniformly over the circumferential direction and the first rotationstopper portion and the second rotation stopper portion may beconstituted by projections projected into the key grooves.

[0213] At any rate, so far as movement of the ferrule in the rotatingdirection can be restricted by the optical connector plug and theoptical connector adapter, an effect similar to those of Embodiments 1through 3, mentioned above, can be achieved.

[0214] Further, although according to Embodiments 1 through 3, mentionedabove, the mounting members 70 through 7 0B are provided with the bentportions 71 for engaging with the fixing holes 101 of the mounting board100 and the mounting members 70, 70A through 70B are mounted on themounting board 100, a method of mounting the mounting members 70, 70Athrough 70B on the mounting board 100 is not particularly limitedthereto.

[0215] Here, other example of a mounting member is shown in FIG. 17.Further, FIG. 17 is a perspective view showing a mounting step showing amodified example of the mounting member of Embodiment 1.

[0216] As shown by FIG. 17, a mounting member 70C is not provided with abent portion and is constituted only by a base sheet portion 72C.

[0217] Fixing projections 72A projected in a face direction are providedon sides of both ends in the longitudinal direction of the base seatportion 72C and sides of bottom faces of the fixing projections 72 a arebonded onto the mounting board 100.

[0218] Further, bonding of the fixing projection 72 a and the mountingboard 100 is not particularly limited but, for example, bonding can becarried out by adhesion via an adhering agent, brazing or soldering.

[0219] Also the mounting member 70C can be formed by metal pressing.

[0220] Further, although according to Embodiments 1 through 3, mentionedabove, the optical connectors 10 through 10B are fixed attachably anddetachably to and from the mounting board 100 via the mounting members70 through 70B fixed thereto attachably and detachably, Embodiments 1through 3 are not particularly limited thereto but, for example, in thecase of the optical connector 10B having the mount engaging portions 64Baccording to Embodiment 3, the optical connector 10B may directly befixed onto the mounting board 100. Even by such a constitution, theoptical connector 10B can be fixed attachably and detachably to and fromthe mounting board 100 and cost can be reduced and downsizing can beachieved by reducing the number of parts of the optical connector,particularly, the number of parts of the optical connector adapter.

[0221] As has been explained above, according to the invention,respectives of the optical connector plug, the optical connector adapterand the mounting member are constituted by reducing the numbers of partsand therefore, the integrating step can be simplified and downsizing canbe achieved by reducing the fabrication cost. Further, the reliabilitycan be promoted without damaging the front end or the like of theoptical fiber in attachment and detachment without restricting thenumber of times of attachment and detachment of the optical connectoradapter and the optical connector plug. Further, since the opticalconnector adapter and the mounting member mounted to the mounting boardare made to be attachable and detachable to and from each other andtherefore, it is not necessary to carry out attachment and detachment ofthe optical connector adapter and the optical connector plug on themounting board and downsizing of the mounting board can be achieved.

What is claimed is:
 1. An optical connector plug comprising: a ferruleincluding a cylindrical member for the ferrule for holding an opticalfiber and a flange member provided at a rear end portion of thecylindrical member for the ferrule; an urge spring provided on a side ofa rear end portion of the flange member of the ferrule; and a plughousing for holding the ferrule and the urge spring directly at insidethereof and directly engaged with an optical connector adapter insertedwith a front end portion of the ferrule to carry out optical connection;wherein the plug housing is formed with a slit capable of inserting theoptical fiber in a radius direction thereof at a portion of an outerperiphery thereof over an axial direction.
 2. The optical connector plugaccording to claim 1, wherein the rear end portion of the flange memberis provided with an engaging portion for engaging with the plug housingand the plug housing includes a holding hole for holding the ferrule ina state of being urged by the urge spring to a front end side in theaxial direction by engaging with the engaging portion of the flangemember and a first rotation stopper portion engaged with the flangemember for restricting movement of the ferrule in a rotating directioncentering on an axis thereof.
 3. The optical connector plug according toclaim 2, wherein the first rotation stopper portion of the plug housingis provided to be able to change relative positions of the plug housingand the ferrule in a state in which the ferrule is pushed against theurge spring.
 4. The optical connector plug according to claim 1, whereinthe flange member is engaged with the optical connector adapter torestrict the ferrule from moving in the rotating direction centering onthe axis of the ferrule.
 5. The optical connector plug according toclaim 2, wherein the flange member includes an outer periphery a sectionof which is rectangular, and the ferrule is restricted from moving inthe rotating direction by bringing the first rotation stopper portioninto contact with two faces of an outer peripheral face of the flangemember on one side opposed to each other and bringing two faces of theflange member on other side into contact with the optical connectoradapter.
 6. The optical connector plug according to claim 1, wherein theouter peripheral face of the flange member is provided with an urgespring engaging projection projected over the circumferential direction,for engaging with the urge spring.
 7. The optical connector plugaccording to claim 1, wherein an outer diameter of the cylindricalmember for the ferrule is 1.25 mm.
 8. An optical connector including theoptical connector plug according to claim
 1. 9. An optical connectoradapter comprising: a sleeve for optical connection inserted withferrules holding optical fibers from sides of both ends thereof forbringing end faces of the ferrules into contact with each other to beconnected optically; and an adapter housing holding the sleeve foroptical connection and optically coupling optical connector plugs heldby the ferrules; wherein an outer periphery of the adapter housing isprovided with a first mount engaging portion attachably and detachablyengaging with a mounting board or a mounting member attachably anddetachably fixed to the mounting board to project from one face thereof.10. The optical connector adapter according to claim 9, wherein theadapter housing comprising: a housing main body provided by integralmolding to open a sleeve inserting hole inserting to hold the sleeve foroptical connection on one side of a side face thereof; and a lid memberfitted to the sleeve inserting hole of the housing main body; whereinthe lid member is integrally provided with the first mount engagingportion projected to a side of other face of the housing main body. 11.The optical connector adapter according to claim 10, wherein engagementof the lid member by the first mount engaging portion is disengaged byan attaching and detaching jig.
 12. The optical connector adapteraccording to claim 11, wherein the attaching and detaching jig isprovided with a shape of a pin and the engagement is disengaged byelastically deforming the first mount engaging portion by inserting theattaching and detaching jig between the first mount engaging portion andthe housing main body.
 13. The optical connector adapter according toclaim 9, wherein the adapter housing is formed by integral molding andthe one face of the adapter housing is provided with a sleeve insertinghole for inserting the sleeve for optical connection.
 14. The opticalconnector according to claim 9, wherein an inner side of an outer edgeof an opening of the sleeve inserting hole is provided with a projectionof the sleeve brought into contact with an outer peripheral face of thesleeve for optical connection for preventing detachment from the sleeveinserting hole.
 15. The optical connector adapter according to claim 9,wherein the side of the other face of the adapter housing is providedwith a second mount engaging portion for engaging with the first mountengaging portion of other one of the adapter housing.
 16. The opticalconnector adapter according to claim 15, wherein a plurality of piecesof the adapter housings are laminated.
 17. The optical connector adapteraccording to claim 9, wherein the adapter housing is provided with asecond rotation stopper portion engaged with an outer periphery of theferrule for restricting the ferrule from moving in a rotating direction.18. An optical connector comprising the optical connector adapteraccording to claim
 9. 19. An optical connector comprising: a ferrulecomprising a cylindrical member for the ferrule holding a front end ofan optical fiber and a flange member fitted to a rear end portionthereof and including an engaging portion on a side of a rear endportion of the flange member; an optical connector plug comprising anurge spring provided on the side of the rear end portion of the flangemember of the ferrule, and a plug housing directly holding the ferrulein a state of being urged to a side of a front end thereof in an axialdirection by the urge spring by being engaged with the engaging portionof the ferrule and provided with a slit capable of inserting the opticalfiber in a radius direction thereof at a portion of an outer peripherythereof over the axial direction and an optical connector adaptercomprising a sleeve for optical connection inserted with the cylindricalmembers for the ferrules from sides of both ends thereof for bringingend faces of the cylindrical members for the ferrules into contact witheach other to optically connect, and an adapter housing holding thesleeve for optical connection and having a shape for optically couplingthe optical connector plugs; wherein the plug housing and the adapterhousing are formed with engaging portions for engaging the plug housingand the adapter housing with each other, an outer periphery of theadapter housing is provided with a first mount engaging portion forattachably and detachably engaging with a mounting board or a mountingmember fixed attachably and detachably to the mounting board to projectfrom one face thereof.
 20. The optical connector according to claim 19,wherein the plug housing is provided with a first rotation stopperportion engaged with the flange member for restricting the ferrule frommoving in a rotating direction centering on an axis thereof and theadapter housing is provided with a second rotation stopper portionengaged with the flange member of the optical connector plug engagedwith the adapter housing for restricting the ferrule from moving in therotating direction centering on the axis of the ferrule.
 21. The opticalconnector according to claim 20, wherein the flange member is providedwith an outer periphery having a section in a rectangular shape and theferrule is restricted from moving in the rotating direction by bringingthe first rotation stopper portion into contact with two faces on oneside of an outer peripheral face of the flange member opposed to eachother and bringing the second rotation stopper portion into contact withtwo faces on other side of the outer peripheral face of the flangemember opposed to each other.
 22. The optical connector according toclaim 19, wherein the plug housing and the adapter housing are providedwith engagement restricting portions for restricting engaging positionsin the rotating direction centering on axes thereof.